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 ###Instrução: Qual é a superfície quando o torneio é disputado em Manta, Equador?
 ###Tabelas: CREATE TABLE singles_7 (singles_7_id AUTO_INCREMENT PRIMARY KEY, Date VARCHAR, Tournament VARCHAR, Surface VARCHAR, Opponent VARCHAR, Score VARCHAR) CREATE TABLE viewing_figures (viewing_figures_id AUTO_INCREMENT PRIMARY KEY, Episode INT, 1st season VARCHAR, 2nd season VARCHAR, 3rd season VARCHAR, 4th season VARCHAR, 5th season VARCHAR, 6th season VARCHAR, 7th season VARCHAR) CREATE TABLE new_zealand_tv2 (new_zealand_tv2_id AUTO_INCREMENT PRIMARY KEY, Episode number INT, Title VARCHAR, Original airing VARCHAR, Timeslot VARCHAR, Viewers INT, Top 50 Ranking INT, Scripted Show Ranking INT) CREATE TABLE belmont_stakes_feature_key_prep_races_list (belmont_stakes_feature_key_prep_races_list_id AUTO_INCREMENT PRIMARY KEY, Date VARCHAR, Track VARCHAR, Race VARCHAR, Distance VARCHAR, Surface track VARCHAR, Winning horse VARCHAR, Winning jockey VARCHAR) CREATE TABLE recent_results_and_forthcoming_fixtures (recent_results_and_forthcoming_fixtures_id AUTO_INCREMENT PRIMARY KEY, Date VARCHAR, Location VARCHAR, Score VARCHAR, Scorers for Chad VARCHAR, Competition VARCHAR)  
SELECT Surface FROM singles_7 WHERE Tournament = manta, ecuador